1. Field of the Invention
The present invention is directed to the field of laser alignment devices.
2. Description of the Related Art
People undertaking construction and repair projects frequently require the use of reference lines. People employ reference lines on projects ranging from professional construction of large city buildings to amateur home improvement. For example, a person installing a border on the walls of a room requires a level reference line on each wall identifying a placement position for the border.
Traditional alignment tools for assisting in the manual placement of reference lines include straight edges, rulers, protractors, squares, levels, and plumb bobs. More recently, tool manufacturers have introduced laser alignment devices that provide references, such as points, lines, and planes. These laser alignment tools include, simple pointers, pointers with bubble vials, self-leveling pointers, multiple beam pointers, and devices producing a sheet of light.
It is desirable for a single alignment tool to provide multiple types of references, so the number of tools required for a job is reduced. In many instances a project requires the use of multiple references. For example, a project may require the use of reference points, lines, and planes. In many instances this requires the use of multiple alignment tools—forcing a person to have all of these tools available for the project. The purchase, maintenance, storage, and transportation of several alignment tools are undesirable inconveniences that consume time and money. In some circumstances it is simply impractical to have multiple alignment tools readily available on a job site.
Laser alignment devices could also benefit from improvements in self-leveling. A number of traditional systems employ a single pendulum self-leveling mechanism. In these devices, the single pendulum must provide leveling, while supporting an optical system connected to the device's power supply. This compromises the pendulum's leveling capability—making the design and manufacture of the single pendulum very difficult. Some single pendulum systems require users to manually provide initial leveling settings to reduce the burden on the single pendulum.
Adjusting the position of references in laser alignment devices provides additional challenges. Precise reference location is hard to achieve, due to the inaccuracies of motors used to position optical components. Cogging stiction in the motors inhibits a user's ability to accurately make small adjustments to a reference's location.
Laser beam alignment during device manufacturing also contributes to the difficulty of accurate reference positioning. Manufacturers traditionally mount laser diodes in alignment devices by placing the diode in a cylindrical casing and press fitting the casing into a cylindrical housing. The housing typically aligns the diode's beam with a lens and reflective optical components. Manufacturers make diode alignment adjustments by rotating and sliding the diode's cylindrical casing within the housing. This limits the degrees of adjustment available to alignment device manufacturers.